1. Field of the Invention
The present invention relates to a method for creating pixel-oriented pictorial datasets for representing graphic symbols with geometric elements and texts by a numerical control.
2. Discussion of Related Art
A modem numerical control represents graphic symbols (icons) on a display screen, which permits the user of a machine tool which is controlled by a numerical control to easily enter commands by functional keys (soft keys), or to receive information regarding the status of the tool or aids regarding the situation at that time in a graphic and therefore easily understandable form. Here, the graphic symbols include two- or three-dimensional objects, which are possibly supplemented by text, or of text only.
Since such numerical controls are used in different countries, it is necessary to adapt the texts of the graphic symbols to the language of the respective country. Since moreover different display devices (display screens) are employed by the users, it is necessary to make the graphic symbols available in the most different resolutions in order to assure easy recognition on the respective display device.
The graphic symbols are stored in a data memory of the numerical control in a pixel-oriented manner, i.e. pixel by pixel. A pictorial editing device is used for producing the graphic symbols, which also operates in a pixel-oriented manner. The outlay for producing all required symbols is large because of the multitude of possible combinations of languages and display screen resolutions, since a single set of graphic symbols can already have several hundred different elements.
If the requirements of the user change, for example because of a new display device of higher resolution, the producer of the control device first must elaborately produce, deliver and install a new set of graphic symbols. This considerably limits the flexibility of such control devices. A simple recalculation of the existing images stored in a pixel-oriented manner to produce a new display screen resolution would lead to fuzzy edges of the graphic symbols.
To become independent of the respective resolution of the display device, it is known to store graphic symbols in a vector-oriented form. However, the outlay for representing such vector graphics increases with the complexity of the objects to be represented and therefore stresses the processor of the numerical control more than the display of pixel-oriented graphics, in particular if three-dimensional images are to be used.
A system, which permits the modification of individual icons by pre-established libraries, is proposed in U.S. Pat. No. 5,689,286, the entire contents of which is incorporated herein by reference. Individual portions of the icons can be changed in a definite manner, and thereafter the icon can again be stored as a pixel-oriented dataset in a memory.
However, the system does not permit the change of the properties of an entire set of graphic symbols.